1. Field of the Inventive concept
The present inventive concept relates to a nonvolatile memory device using a resistance material and a method of driving the nonvolatile memory device.
2. Description of the Related Art
Examples of nonvolatile memories using resistance materials include phase-change random access memories (PRAMs), resistive RAMs (RRAMs), and magnetic RAMs (MRAMs). Dynamic RAMs (DRAMs) or flash memories typically store data by applying a charge trapping mechanism. Nonvolatile memories using resistance materials, on the other hand, store data according to a change in an electrical resistance, or state change, of a phase-change material such as chalcogenide alloy (in the case of PRAMs), a resistance change of a variable resistance material (in the case of RRAMs), or a resistance change of a magnetic tunnel junction (MTJ) thin film according to a magnetization state of a ferromagnetic material (in the case of MRAMs).
In particular, a phase-change material of a PRAM can be at a crystalline state or an amorphous state as it is cooled after being heated. The phase-change material has low a resistance in the crystalline state and has a high resistance in the amorphous state. Therefore, the crystalline state may be defined as set data or data 0, and the amorphous state may be defined as reset data or data 1.